US Daylight Saving Time and the Time Difference with Japan

The US rule

Since 2007, under changes made by the Energy Policy Act of 2005, US daylight saving time starts at 2:00 a.m. local time on the second Sunday of March, when clocks jump to 3:00, and ends at 2:00 a.m. on the first Sunday of November, when clocks fall back to 1:00.

In 2026 it runs from March 8 to November 1. In 2027 it runs from March 14 to November 7. Each time zone switches at its own 2:00 a.m., so the change sweeps west an hour at a time. Before 2007, the period ran from the first Sunday in April to the last Sunday in October, so older references can be misleading.

Time differences from Japan

Japan Standard Time is UTC+9 all year. During daylight saving time, US clocks move an hour closer to Japan's. A 9:00 a.m. meeting in New York is 11:00 p.m. the same day in Tokyo during standard time and 10:00 p.m. during daylight time. A 9:00 a.m. meeting in Los Angeles is 2:00 a.m. the next day in Tokyo in winter and 1:00 a.m. in summer.

Alaska (UTC−9, with DST) is 18 hours behind Japan, or 17 in summer.

• Eastern (New York, Washington): 14 hours behind; 13 during DST
• Central (Chicago, Dallas): 15 behind; 14 during DST
• Mountain (Denver): 16 behind; 15 during DST
• Arizona (Phoenix): 16 behind all year
• Pacific (Los Angeles, Seattle): 17 behind; 16 during DST
• Hawaii: 19 behind all year

Arizona and Hawaii

Hawaii and Arizona do not observe daylight saving time, and neither do Puerto Rico, Guam and other US territories. The Navajo Nation in Arizona is an exception and does observe it.

Because Arizona stays on Mountain Standard Time, in summer its clocks match Pacific Daylight Time. In July, Phoenix and Los Angeles show the same time, both 16 hours behind Japan. In winter, Los Angeles falls back and they are an hour apart again. It is safer to confirm by city than by state or zone name.

Meetings shift around the switch

Which way a recurring meeting moves depends on whose clock it is anchored to. A call fixed at 9:00 a.m. Monday New York time moves from 11:00 p.m. to 10:00 p.m. in Tokyo after the March switch and back after November's. A call fixed at 9:00 a.m. Monday Tokyo time moves on the US side: on March 2, 2026 it is 7:00 p.m. Sunday in New York, but on March 9, after the switch, it is 8:00 p.m. Sunday.

The switch days themselves have odd hours. On March 8 in New York, 2:00 to 3:00 a.m. does not exist: 3:00 p.m. in Tokyo is 1:00 a.m. there, and 4:00 p.m. in Tokyo is 3:00 a.m. On November 1 the 1:00 a.m. hour happens twice, so 3:00 p.m. and 4:00 p.m. in Tokyo both fall within it.

Europe switches on different dates

The EU and the UK switch on the last Sunday of March and the last Sunday of October, all at 01:00 UTC. In 2026 that is March 29 and October 25; in 2027, March 28 and October 31.

So for about three weeks in March and one week around the end of October, only one side is on summer time. In 2026, from March 8 to 28 and from October 25 to 31, New York is four hours behind London instead of five. At 5:00 p.m. Tokyo time on March 20, 2026 it is 8:00 a.m. in London and 4:00 a.m. in New York; on March 30 the same Tokyo time is 9:00 a.m. in London and still 4:00 a.m. in New York. Three-region meetings deserve a check every spring and autumn.

Avoiding mistakes

Always pair a time with a date and a weekday, and say which city's clock is fixed, for example "Tuesday, March 10, 9:00 Tokyo = Monday, March 9, 20:00 New York." The Japan–US time converter checks the date to decide whether daylight time applies, and the time difference calculator gives the length between two times. DST rules can change by law, and making it permanent is still debated, so double-check close to important dates.